DFU thread Server nrfutil ncp connectivity issue

[pawel3cte]

Hi,

I've been trying any way I can think of to work around an issue "51" returned by nrfjprog executed from nrfutil when trying to run serwer from the steps in tutorial:
https://devzone.nordicsemi.com/nordic/short-range-guides/b/mesh-networks/posts/thread-tutorial-practical-guide-for-device-upgrade-ota

It ends up with:

File "subprocess.py", line 512, in run
subprocess.CalledProcessError: Command '['nrfjprog', '--snr', '683191406', '--verify', '/tmp/_MEI0grNYG/nordicsemi/thread/hex/ncp.hex', '--family', 'NRF52']' returned non-zero exit status 51.

I had tried to program ncp.hex from source package of the same nrfutil version and next I tried to use nrfutil without '--flash_connectivity' but then I get:

2020-12-17 09:48:42,784 Failed to reset NCP. Please flash connectivity firmware.

I tried doing it on Linux and Windows machine. I tried different relese( v5.2.0 ). All gives nothing but errors.

[pawel3cte]

I got some progress: second try using manually programmeg ncp succeeded. I lost a lot of my time because I didn't try twice I tried different methods instead.

pawp@DESKTOP031 MINGW32 ~/Downloads
$ ./nrfutil_v5_2.exe --verbose dfu thread -snr 683741244 --panid 1234 --masterkey [my key] -pkg update_candidates/app_dfu_package.zip
Address not specified. Using ff03::1 (all Thread nodes)
Using connectivity board at serial port: COM6
2020-12-17 11:10:50,441 Failed to reset NCP. Please flash connectivity firmware.
Traceback (most recent call last):
  File "nordicsemi\__main__.py", line 1382, in thread
  File "nordicsemi\thread\tncp.py", line 224, in open
Exception: Failed to reset NCP. Please flash connectivity firmware.

pawp@DESKTOP031 MINGW32 ~/Downloads
$ ./nrfutil_v5_2.exe --verbose dfu thread -snr 683741244 --panid 1234 --masterkey [my key] -pkg update_candidates/app_dfu_package.zip
Address not specified. Using ff03::1 (all Thread nodes)
Using connectivity board at serial port: COM6
Waiting for NCP to promote to a router...
Thread DFU server is running... Press <Ctrl + D> to stop.

Can someone confirm/explain this bug?